478061 A7 五、發明說明（1 ) 發明背景 本發明係關於一種蝕刻矽半導體晶圓之鹼性蝕刻溶液及 方法，彳目較於習知鹼性蝕刻溶液，以詨鹼性蝕刻溶液所製 備之晶圓具有減少粗糙度的極平滑表面。 矽半導體晶圓通常係由下列步驟得到：在垂直鑄料軸的 方向切下一塊單晶矽鑄料來製備薄晶圓，修整該晶圓的邊 緣，研磨或磨光該晶圓以除去由切削過程所致的表面損傷 ，化學蝕刻孩晶圓以除去由先前塑型步驟所產生的機械損 傷，最後，化學/機械拋光該邊緣，且各晶圓至少有一面係 以例如一種膠狀氧化矽淤漿及一種化學蝕刻劑來拋光，以 確保晶圓具有極平滑、反射性且無損傷的表面。然後在包 裝之前通常會清洗該晶圓並檢視其品質。 在化學蝕刻之前，矽半導體晶圓通常呈現表面及/或表面 下的瑕疵，例如嵌入微粒及經由上游過程（如磨光、研磨及 整邊）所給予晶圓的物理損傷（如微裂缝、破裂或應力）。這 些瑕疵通常發生在彳足聂圓奉面延伸到晶圓表面下至少約2 5 微米或更大的區域。爲了晓去這些瑕疵，因此利用一種酸 性或鹼拉勉刻劑從晁圓_表面除去！少2乃雇米姑原料，藉此 除去皂含在—原料—層—中-的廉入微粒、冷—染物及-物理报傷。 一般而言，鹼性蝕刻溶液提供幾個優於酸蝕刻溶液的好 處。比如説，利用相當簡單的蝕刻設備，鹼性蝕刻易於製 得比酸蝕刻溶液所蝕刻之晶圓具有更均勻平滑表面的晶圓 。此外，、驗性餘刻务液可提供;?夕極佳的保—護，預防金屬广给 ,了鐵之外）的沈積，因爲金屬轉換成不溶的沈澱物或可溶鹽 ^紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注音？事項再填寫本頁) Η^τ.. :線- 經濟部智慧財產局員工消費合作社印製 4- 478061 Α7 Β7 五、發明說明（2 ) 類會造成有少量污染物的表面。 ' —. 一 除了改善所得晶圓的品質外’驗性姓刻方法本身較酸方 法安全且成本較低。由鹼性蝕刻方法所產生之氣態副產物 無毒性，然而酸蚀刻劑，其通常包含硝酸，會產生氮的氧 化物（N0X)成爲酸蚀刻方法的氣態副產物。n〇x對人體有毒 ，而且要從流出物氣體中將其除去以免污染環境並符合環 境管制要求往往非常困難且所費不貲。除此之外，驗性蝕 刻溶液與皮膚細胞組織的反應往往比酸蝕刻溶液慢，對操 作人員而言意外暴露於驗性蚀刻溶液比酸姓刻溶液較不危 險。 然而，鹼性蝕刻溶液並非各方面都優於酸蝕刻溶液。相 較於由酸蚀刻方法所蚀刻的晶圓，經過驗性蚀刻方法的晶 圓常常在晶圓表面和邊緣呈現不規則性，例如一種多棱 (faceted)表面，其顯現出一種增加的表面粗糙度。表面粗 糙度可在隨後的拋光步驟中減少；然而，要產生可接受表 面所需的拋光時間則隨增加的表面粗糙度而大大地增加。 此外，一些裝置製造商要求晶圓背面維持”如經蚀刻的 (as etched) ”。以驗性蚀刻溶液蚀刻晶圓，製得的晶圓具有 無法接受之表面粗糙度之”如經蝕刻的π背面特徵。因此， 半導體製造商通常考量伴隨鹼性蚀刻溶液的表面粗糙度問 題更甚於驗性蚀刻的好處，因此使用酸性蚀刻溶液。 一個嘗試提供利用驗性蚀刻溶液來製造半導體晶圓的方 法係在美國專利案號5,494,862中提出。U.S·專利案號 5,494,862揭示一種方法，其中使用濃氫氧化鈉或氫氧化舞 -5- 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製478061 A7 V. Description of the invention (1) Background of the invention The present invention relates to an alkaline etching solution and method for etching silicon semiconductor wafers. Compared with the conventional alkaline etching solution, the crystal is prepared by using the alkaline etching solution. The circle has an extremely smooth surface with reduced roughness. Silicon semiconductor wafers are usually obtained by cutting a single crystal silicon casting in the direction of the vertical casting axis to prepare a thin wafer, trimming the edges of the wafer, and grinding or polishing the wafer to remove the Surface damage caused by the process, chemically etching the child wafer to remove the mechanical damage caused by the previous molding step, and finally, chemically / mechanically polishing the edge, and at least one side of each wafer is coated with, for example, a colloidal silicon oxide silt Slurry and a chemical etchant to polish the wafer to ensure a very smooth, reflective and non-damaging surface. The wafer is usually cleaned and inspected for quality before packaging. Prior to chemical etching, silicon semiconductor wafers often exhibit surface and / or subsurface defects, such as embedded particles and physical damage (such as microcracks, cracks) to the wafer through upstream processes (such as polishing, grinding, and trimming) Or stress). These imperfections usually occur in areas where the flattened surface extends below the surface of the wafer at least about 25 microns or more. In order to get rid of these flaws, we use an acidic or alkaline drawing agent to remove it from the surface! Shao 2 is the raw material of Migu, in order to remove the cheap particles, cold dyes and physical injuries contained in the-raw materials-layer-medium. In general, alkaline etching solutions provide several advantages over acid etching solutions. For example, with relatively simple etching equipment, alkaline etching can easily produce wafers with a more uniform and smooth surface than wafers etched by acid etching solutions. In addition, the test solution can be provided; excellent protection-protection, to prevent the metal from being widely distributed (outside of iron), because the metal is converted into insoluble precipitates or soluble salts. ^ Paper size applies China National Standard (CNS) A4 Specification (210 X 297 mm) (Please read the phonetic on the back? Matters before filling out this page) Η ^ τ ..: Line-Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs Consumer Cooperatives 4-478061 Α7 Β7 V. Description of the invention (2) Type will cause a surface with a small amount of pollutants. '—. In addition to improving the quality of the wafers obtained, the' surrogate surname method 'itself is safer and less expensive than the acid method. The gaseous by-products produced by the alkaline etching method are non-toxic. However, the acid etchant, which usually contains nitric acid, will produce nitrogen oxides (NOx) as the gaseous by-products of the acid etching method. Nox is toxic to the human body, and it is often very difficult and expensive to remove it from the effluent gas to avoid polluting the environment and complying with environmental regulations. In addition, the reaction of the etch solution to the skin cell tissue is often slower than that of the acid etch solution, and accidental exposure to the etch solution by the operator is less dangerous than the acid etch solution. However, the alkaline etching solution is not superior to the acid etching solution in all aspects. Compared to wafers etched by acid etching methods, wafers subjected to empirical etching methods often exhibit irregularities on the surface and edges of the wafer, such as a faceted surface that exhibits an increased surface roughness degree. Surface roughness can be reduced in subsequent polishing steps; however, the polishing time required to produce an acceptable surface greatly increases with increasing surface roughness. In addition, some device manufacturers require wafer backs to be maintained "as etched". The wafer is etched with an empirical etching solution, and the resulting wafer has unacceptable surface roughness characteristics such as etched π back surface characteristics. Therefore, semiconductor manufacturers usually consider the surface roughness problem with alkaline etching solutions even more. Because of the benefits of empirical etching, an acidic etching solution is used. An attempt to provide a semiconductor wafer using the etch etching solution is proposed in US Patent No. 5,494,862. US Patent No. 5,494,862 discloses a method in which the use of Concentrated sodium hydroxide or hydroxide hydroxide-5- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page) Employees ’Intellectual Property Bureau of the Ministry of Economic Affairs Consumption Printed by a cooperative
478061 A7 B7 五、發明說明（3 ) 溶液（如4 5重量％氫氧化#1溶液）來蚀刻晶圓。經蚀刻晶圓 隨後呈現如以上討論由驗性蝕刻所致之增加的表面粗糙度 。爲了減少由鹼性蚀刻所致之表面粗糙度，U · S .專利案號 5,494,862除了拋光晶圓正面之標準實行外還要求一種輕度 (light)背面抛光，因此同時增加了整個方法的複雜性和成 本。此外，由習知鹼性蚀刻劑所致之增加的表面粗糙度通 常會使拋光晶圓正面和側面所需的抛光時間增加，因而降 低生產量且增和整個方法的成本。 發明摘述 因此，在本發明之目的中，可提及的有··鹼性蚀刻溶液 的提供；一種利用該溶液製備均勻蚀刻之晶圓的方法；蝕 刻用驗性蝕刻溶液及方法的提供，其中經蝕刻晶圓具有比 <習如驗性蚀刻溶液所蚀刻之晶圓減少的表面粗糙度；姓刻 用驗性蚀刻溶液及方法的提供，其具有優於酸性蚀刻之加 強安全性的特徵；蝕刻用驗性蝕刻溶液及方法的提供，其 ?文一善隨後拋光步驟的生產量；以及蝕刻用鹼性蝕刻溶液及 方法的提供’其減少毒性發散物的量及/或環境控制的成本。 經濟部智慧財產局員工消費合作社印製 (請先閱讀背面之注意事項再填寫本頁) 線· 故簡而T之’本發明係針對一種蝕刻矽半導體晶圓的方 法’其中该晶圓係經受一種驗性姓刻溶液，其包含約2 5至 約6 5重f %鹼及約〇 5至約1 〇重量％氧化劑，其中該鹼包 含一種金屬氫氧化物且該氧化劑包含過氧化氫或臭氧。 本發明之其他目的和特色將部分顯而易見而部份於下文 指出。 圖式簡要説明 -6- 本紙張尺度_ t _家標準（CJNS)A4規格（210 X 297公爱） 1/OUO 丄 經濟部智慧財產局員工消費合作社印製 A7 B7 、發明說明（ 、圖1爲一種長條圖，其表示P -晶圓表面粗糙度爲蝕刻劑組 成的函數，如實例1所説明。 、圖2爲一種長條圖，其表示？+晶圓表面粗糙度爲蝕刻劑組 成的函數，如實例2所説明。 表1表示本發明對邊緣粗糙度和拋光時間的影響，如實例 3所說明。 體實例的諱細説明 令人驚野地’已發現到一種蚀刻矽半導體晶圓的方法， 其中該晶圓係經受一種含鹼與氧化劑的鹼性蝕刻溶液，其 提供鹼性蝕刻的加強好處，同時製得具有比習知鹼性蚀刻 溶液所蚀刻晶圓減少之表面粗糙度的晶圓。 本發明之方法係設計來利用一種含鹼與氧化劑的鹼性蚀 刻溶液從晶圓表面除去至少約2·5微米的原料，藉此除去表 面及表面下的瑕疵，例如嵌入微粒和機械損傷〈如在切射、 研磨及/或磨光方法步驟期間所給予晶圓者），如此一來所 知曰曰'圓具有勝過以典型鹼性蝕刻溶液所蝕刻晶圓之減少的 粗糙程度。以本發明蝕刻溶液所製備之晶圓在蚀刻後具有 更#勻的平度和減少的粗糙度，如此一來隨後拋光時間 便大大地減少。 含鹼與氧化劑之鹼性溶液先前曾被用來作爲清潔溶液， 其中稀釋㈣性氫氧化物結合氧化劑—同使用，以反覆地 氧^晶圓表面產生一種二氧化矽薄層，其之後立刻被鹼性 成刀彳疋表面蝕刻，由此從晶圓表面除去污染物。參見例如 U.S·專利案號5,489,557與曰本專利申請書案號〇6_ (請先閱讀背面之注意事項再填寫本頁)478061 A7 B7 V. Description of the invention (3) A solution (such as a 45% by weight hydroxide # 1 solution) is used to etch the wafer. The etched wafer then exhibits an increased surface roughness caused by the etch as discussed above. In order to reduce the surface roughness caused by alkaline etching, U.S. Patent No. 5,494,862 requires a light back polishing in addition to the standard implementation of polishing the front side of the wafer, thus increasing the complexity of the entire method at the same time. And cost. In addition, the increased surface roughness caused by conventional alkaline etchants often increases the polishing time required to polish the front and side of the wafer, thereby reducing throughput and increasing the cost of the overall process. SUMMARY OF THE INVENTION Therefore, in the purpose of the present invention, mention may be made of the provision of an alkaline etching solution; a method for preparing a uniformly etched wafer using the solution; the provision of an etch etching solution and a method for etching, Among them, the etched wafer has a reduced surface roughness than the wafer etched by the conventional etching solution, and the provision of the experimental etching solution and method for engraving has the characteristics of enhanced safety superior to the acid etching ; Provision of an etch etching solution and method for etching, which is the production volume of a subsequent polishing step; and provision of an alkaline etching solution and method for etching, which reduce the amount of toxic emissions and / or the cost of environmental control. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling this page). So the short "The invention is a method for etching silicon semiconductor wafers", where the wafers are subjected to An empirical solution containing about 25 to about 65 weight percent f base and about 0.05 to about 10 weight percent oxidant, wherein the base comprises a metal hydroxide and the oxidant comprises hydrogen peroxide or ozone . Other objects and features of the present invention will be partially obvious and partially pointed out below. Schematic description-6- This paper size _ t _ Home Standard (CJNS) A4 specification (210 X 297 public love) 1 / OUO 丄 Printed A7 B7, Invention Description (, Figure 1) Is a bar graph showing that P-wafer surface roughness is a function of the etchant composition, as illustrated in Example 1. Figure 2 is a bar graph showing? + Wafer surface roughness is the etchant composition Function, as illustrated in Example 2. Table 1 shows the effect of the present invention on edge roughness and polishing time, as illustrated in Example 3. The detailed description of the practical example is surprisingly 'an etched silicon semiconductor wafer has been found Method, wherein the wafer is subjected to an alkaline etching solution containing an alkali and an oxidant, which provides the enhanced benefits of alkaline etching, while producing a wafer having a surface roughness that is reduced compared to a conventional alkaline etching solution. Wafer. The method of the present invention is designed to remove at least about 2.5 micrometers of raw materials from the surface of the wafer using an alkaline etching solution containing an alkali and an oxidant, thereby removing surface and subsurface defects such as embedded particles. Mechanical damage (such as those given to the wafer during the cutting, grinding, and / or polishing method steps), so known that 'roundness has reduced roughness over wafers etched with typical alkaline etching solutions degree. The wafer prepared by using the etching solution of the present invention has more uniform flatness and reduced roughness after etching, so that the subsequent polishing time is greatly reduced. An alkaline solution containing an alkali and an oxidant has previously been used as a cleaning solution, in which a dilute hydroxide hydroxide is combined with an oxidant—also used to repeatedly oxidize the surface of the wafer to produce a thin layer of silicon dioxide, which is immediately thereafter The alkaline etched surface is etched, thereby removing contaminants from the wafer surface. See, for example, U.S. Patent Case No. 5,489,557 and Japanese Patent Application Case No. 06_ (Please read the notes on the back before filling this page)
45281 a然而，此等清潔方法僅係設計用來清潔晶圓表面 ’且一通常從晶圓表面除去小於1微米且更常的是除去小於約 1〇〇愛微米的原料。再者，該清料液從晶圓表面除去原料 的速率下降得很快，如此一來清潔溶液無法除去足量的原 料以消除上述的瑕疵，即使令其接觸清潔溶液一段延長的 時間亦然。因此，雖然清潔溶液可能除去一些原料，但所 于、去原料的里小於除去上述之嵌入微粒、〉、亏染物及物理損 知所需量好幾個數量級。相對地，鹼與氧化劑在本發嗯鹼 性蚀刻溶液中的濃度則是使鹼的蝕刻效果大於氧化劑的氧 化效果’淨效果則是從晶圓表面除去原料。 本發明之方法使用一種矽半導體晶圓作爲起始物，從單 晶矽鑄料將其切下，並利用習知研磨裝置進一步加工，以 修整該晶圓的周緣並粗略地改善其正面與背面的大致平滑 度和平行度。因此，利用熟諳此技藝者所知的任何裝置（如 内控切削裝置或鐵線銀（wiresaw)切削裝置）便可從鑄料切 下晶圓。此外，一旦從鑄料切下晶圓，最好使晶圓的周緣 成圓形以降低在進一步加工期間該晶圓損傷的風險。之後 使晶圓經受一種習知研磨方法以減少由切削方法所致之不 均勾損傷’並改善晶圓的平行度和平滑度。此等研磨方法 係爲熟諳此技藝者所熟知。典型的研磨方法通常係利用如 一種樹脂黏合之12〇〇至6000目轉輪（以約2000 RPM至約4000 RPM操作）從各表面除去約2 〇微米至約3 〇微米的原料而粗 略地改善平滑度。 石夕半導體晶圓可具有任何適合半導體應用的電導率類型 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 訂： •線· 經濟部智慧財產局員工消費合作社印製 478061 A7 B7 五、發明說明（6 ) (請先閱讀背面之注意事項再填寫本頁) 和電阻率。此外，晶圓可具有任何適合半導體應用的直徑 和目標厚度。例如，直徑通常爲至少約1〇〇毫米，且典型爲 150毫米、200毫米、300毫米或更大，而厚度可從約475至 約900微米或更大，厚度通常隨直徑增加而增加。晶圓亦可 具有任意的晶體方位。然而，一般而言，晶圓具有一種 <100>或<111>晶體方位。 從鑄料切下並經上述機械塑造方法後，晶圓通常呈現表 面及/或表面下的瑕疵，例如嵌入微粒及經由上游程序（如 磨光、研磨及整邊）所給予晶圓的物理損傷（如微裂缝、破 裂或應力）。這些瑕疵通常發生在從晶圓表面延伸到晶圓表 面下至少約2.5微米或更大的區域。除此之外，晶圓表面通 常具有至少約5 0毫微米至約100毫微米或更大的表面粗糙度 。表面粗糙度可利用任何能夠測量表面粗糙度的度量衡裝 置來測量。此等裝置在此技藝中係爲眾人所熟知的。比如 説，表面粗糙度可利用下列裝置測量：一種MP300表面測 量裝置，其可在市面上從柴普曼儀器（Chapman Instruments， Rochester，NY)購得，或其他度量衡裝置，例如一種AF Μ顯 微鏡，一種50Χ倍率的諾馬司基（Nomarski)顯微鏡，一種具 10X倍率之Wyko-2D顯微鏡，或一種光學干涉儀。 經濟部智慧財產局員工消費合作社印製 本發明使用一種鹼性蚀刻溶液從晶圓表面除去足量的原 料（至少約2 · 5微米或更多），如此一來便可除去包含上述瑕 疵的區域。此外，本發明可用來消除任何其他的表面或表 面下的瑕疵，藉由從晶圓表面除去原料或僅僅由晶圓表面 降去所需的原料量便可除去該瑕疵。 -9 - 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 經濟部智慧財產局員工消費合作社印製 478061 A7 B7__ 五、發明說明（7 ) 因此，依據本發明，使晶圓表面接觸一種蝕刻溶液一段 充分時間，以便從晶圓表面除去所需的原料量。在一較佳 具體實例中，該晶圓係單獨或隨同多個晶圓浸潰於一種蚀 刻溶液中，以從晶圓表面除去足量的原料，如此一來便可 消除位於所除去區域的瑕疵。雖然在單一浴中所蝕刻的精 確晶圓數目並無嚴格限制，但通常一次蚀刻2 5個晶圓，其 中該晶圓係縛在一支架上並在蚀刻過程中旋轉。旋轉速率 並非絕對重要，然而其通常在每分鐘約5至約100轉變化。 或者，可藉由自旋蚀刻使晶圓表面接觸蚀刻溶液，其中將 晶圓之一面置於可旋轉夾盤上，然後將蝕刻溶液噴塗在連 接夾盤表面的相反面上，同時以高速旋轉晶圓。雖然無嚴 格限制，夾盤上晶圓之旋轉速度範圍係從每分鐘約10至約 1000 轉。 該蚀刻溶液包含一種驗與一種氧化劑，其中該驗係由一 種金屬氫氧化物（如氫氧化鈉或氫氧化鉀）所組成且該氧化 劑係由過氧化氫及/或臭氧所組成。再者，該蝕刻溶液爲約 2 5至6 5重量％鹼，更佳約4 5至5 0重量％鹼，及約0.5至約 1 0重量％，較佳約0.6至約6重量％且最佳約0.6至3重量％ 氧化劑。再者，鹼與氧化劑及隨後之蝕刻溶液的純度，雖 然無嚴格限制，但應該至少要足夠一般半導體晶圓加工使 用。較佳，該鹼與氧化劑遵從如半導體設備與材料國際標 準(Semiconductor Equipment and Materials International standards)(以下稱SEMI標準）中所提出的純度描述。比如説 ，符合或超過SEMI驗標準的電子級（electronics grade)過氧 -10- 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）~ (請先閱讀背面之注意事項再填寫本頁) -% . · 478061 經濟部智慧財產局員工消費合作社印製 A7 _B7__五、發明說明（9 ) 度，其中蚀刻劑濃度的減少係與從表面除去的物質量有直 接關係。因此，蝕刻劑濃度的減少可用來預測所除去的原 料量。蝕刻劑濃度可利用熟諳此技藝者所知的任何方法來 測量，且可經由例如感應偶合等離子磁化光譜來測定。熟 請此技藝者可利用相關技藝所知的任何工具來測定所除去 原料的量，而不達背本發明之範鲁。 所得晶圓具有減少的表面及表面下的瑕疵，其中已消除 位於從晶圓除去之矽層的嵌入微粒和物理瑕疵，且所得晶 圓表面具有範圍從約1，〇〇〇至約2800A的粗糙度，如利用一 種MP 3 00型表面測量裝置所測量的。 蝕刻之後，利用習知拋光技術拋光該晶圓。具有比習知 鹼性蝕刻劑所蝕刻晶圓減少之粗糙度的晶圓需要較少時間 做隨後的邊緣與切口拋光步驟。舉例言之，在一較佳具體 實例中，在晶圓經由本發明蚀刻之後，利用一種Speedfam £1) 3 00邊緣拋光裝置（市面上可從8卩66(1£3111〇〇.(1(^1^83\\^， Japan)購得）拋光該晶圓的邊緣和切口，其中將一種磨蚀塾 板（如一種市面上可從羅得爾公司（Rodel Co.，Newark， Delaware)購得之Suba4磨蚀蟄板）連接於一個轉鼓的表面， 之後以大約600至1，000 RPM轉動之，並對晶圓表面施加約 1，600至約2,000克力的拋光壓力，同時塗用一種含膠狀氧化 矽淤漿與約1至約3 %氫氧化鉀的拋光淤漿。拋光經由本發 明蝕刻到約3 0至約500A粗糙度之標準200毫米晶圓的邊緣 所需的時間量大約1 . 5至2分鐘，而拋光習知鹼性蚀刻劑所 蝕刻晶圓所需的時間則爲3至4分鐘。拋光經由本發明蝕刻 請 先 閱 讀 背 面 之 注 意 項45281 a However, these cleaning methods are only designed to clean the surface of the wafer ′ and one typically removes less than 1 micron from the wafer surface and more often removes less than about 100 micrometers of raw material. Furthermore, the rate at which the cleaning solution removes the raw material from the wafer surface decreases rapidly. As a result, the cleaning solution cannot remove a sufficient amount of raw material to eliminate the aforementioned defects, even if it is exposed to the cleaning solution for an extended period of time. Therefore, although the cleaning solution may remove some of the raw materials, the amount of the raw materials removed is several orders of magnitude smaller than the amount required to remove the above-mentioned embedded particles, stains, and physical damage. In contrast, the concentration of the alkali and the oxidant in the basic etching solution of the present invention is such that the etching effect of the alkali is greater than the oxidation effect of the oxidant. The net effect is to remove raw materials from the wafer surface. The method of the present invention uses a silicon semiconductor wafer as a starting material, cuts it from a single crystal silicon casting material, and further processes it using a conventional grinding device to trim the periphery of the wafer and roughly improve its front and back sides. The approximate smoothness and parallelism. Therefore, any device known to those skilled in the art, such as an internal control cutting device or a wiresaw cutting device, can be used to cut the wafer from the cast material. In addition, once the wafer is cut from the cast, it is best to round the periphery of the wafer to reduce the risk of damage to the wafer during further processing. The wafer is then subjected to a conventional polishing method to reduce uneven damage caused by the cutting method 'and to improve the parallelism and smoothness of the wafer. These grinding methods are well known to those skilled in the art. A typical grinding method generally uses a resin-bonded 12000 to 6000 mesh runner (operating at about 2000 RPM to about 4000 RPM) to remove about 20 microns to about 30 microns of raw material from each surface to improve roughly. Smoothness. Shixi Semiconductor wafers can have any conductivity type suitable for semiconductor applications. The paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling out this page) Order: • Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 478061 A7 B7 V. Description of Invention (6) (Please read the precautions on the back before filling this page) and resistivity. In addition, the wafer can have any diameter and target thickness suitable for semiconductor applications. For example, the diameter is usually at least about 100 millimeters, and typically 150 millimeters, 200 millimeters, 300 millimeters or more, and the thickness can be from about 475 to about 900 micrometers or more, and the thickness generally increases as the diameter increases. The wafer can also have any crystal orientation. However, in general, the wafer has a < 100 > or < 111 > crystal orientation. After being cut from the cast material and subjected to the above-mentioned mechanical shaping methods, the wafer usually exhibits surface and / or subsurface defects such as embedded particles and physical damage to the wafer through upstream processes such as buffing, grinding and trimming (Such as micro-cracks, cracks, or stress). These defects typically occur in areas that extend from the wafer surface to at least about 2.5 microns or more below the wafer surface. In addition, the wafer surface typically has a surface roughness of at least about 50 nm to about 100 nm or more. Surface roughness can be measured using any metrology device capable of measuring surface roughness. These devices are well known in the art. For example, the surface roughness can be measured using an MP300 surface measuring device, which is commercially available from Chapman Instruments (Rochester, NY), or other metrology equipment, such as an AF MM microscope, A 50X magnification Nomarski microscope, a 10X magnification Wyko-2D microscope, or an optical interferometer. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs This invention uses an alkaline etching solution to remove a sufficient amount of raw materials (at least about 2.5 microns or more) from the wafer surface, so that the area containing the above defects can be removed . In addition, the present invention can be used to eliminate any other surface or subsurface defects, which can be removed by removing the raw material from the wafer surface or simply reducing the required amount of raw material from the wafer surface. -9-This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 478061 A7 B7__ 5. Description of the invention (7) Therefore, according to the present invention, the crystal The round surface is exposed to an etching solution for a sufficient period of time to remove the required amount of raw material from the wafer surface. In a preferred embodiment, the wafer is immersed in an etching solution alone or with multiple wafers to remove a sufficient amount of raw material from the wafer surface, so that defects in the removed area can be eliminated. . Although the number of precise wafers etched in a single bath is not strictly limited, usually 25 wafers are etched at a time, where the wafers are tied to a holder and rotated during the etching process. The rotation rate is not absolutely important, however it usually varies from about 5 to about 100 revolutions per minute. Alternatively, the surface of the wafer may be contacted with an etching solution by spin etching, in which one side of the wafer is placed on a rotatable chuck, and then the etching solution is sprayed on the opposite side of the surface connected to the chuck while rotating the crystal at high speed circle. Although there is no strict limit, the rotation speed of the wafer on the chuck ranges from about 10 to about 1000 revolutions per minute. The etching solution includes a test and an oxidant, wherein the test is composed of a metal hydroxide (such as sodium hydroxide or potassium hydroxide) and the oxidant is composed of hydrogen peroxide and / or ozone. Furthermore, the etching solution is about 25 to 65 wt% alkali, more preferably about 45 to 50 wt% alkali, and about 0.5 to about 10 wt%, preferably about 0.6 to about 6 wt% and most It is preferably about 0.6 to 3% by weight of an oxidizing agent. In addition, although the purity of the alkali, the oxidant and the subsequent etching solution is not strictly limited, it should be at least sufficient for general semiconductor wafer processing. Preferably, the base and the oxidizing agent follow the purity description as proposed in Semiconductor Equipment and Materials International standards (hereinafter referred to as SEMI standards). For example, electronic grade peroxygen that meets or exceeds the SEMI inspection standard-10- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ~ (Please read the precautions on the back before (Fill in this page)-%. · 478061 Printed by A7 _B7__ of the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the invention (9), in which the reduction of the etchant concentration is directly related to the amount of material removed from the surface. Therefore, a decrease in etchant concentration can be used to predict the amount of raw material removed. The etchant concentration can be measured by any method known to those skilled in the art, and can be measured via, for example, inductively coupled plasma magnetization spectroscopy. Those skilled in the art can use any tool known in the relevant art to determine the amount of raw material removed without departing from the scope of the present invention. The resulting wafer has reduced surface and subsurface defects, in which embedded particles and physical flaws in the silicon layer removed from the wafer have been eliminated, and the resulting wafer surface has a roughness ranging from about 1,000 to about 2800A Degrees, as measured using a MP 3 00 surface measuring device. After etching, the wafer is polished using conventional polishing techniques. Wafers with reduced roughness compared to conventional alkaline etched wafers require less time for subsequent edge and cut polishing steps. For example, in a preferred embodiment, after the wafer is etched by the present invention, a Speedfam £ 1) 3 00 edge polishing device (available on the market from 8 卩 66 (1 £ 3111〇〇. (1 ( ^ 1 ^ 83 \\ ^, commercially available from Japan) to polish the edges and cuts of the wafer, in which an abrasion mask (such as a commercially available one from Rodel Co., Newark, Delaware) Suba4 abrasion cymbal plate) is connected to the surface of a rotating drum, and then it is rotated at about 600 to 1,000 RPM, and a polishing pressure of about 1,600 to about 2,000 grams of force is applied to the surface of the wafer. Colloidal silicon oxide slurry with a polishing slurry of about 1 to about 3% potassium hydroxide. The amount of time required to polish an edge of a standard 200 mm wafer with a roughness of about 30 to about 500 A via the present invention is about 1 5 to 2 minutes, and the time required to polish a wafer etched by a conventional alkaline etchant is 3 to 4 minutes. Please read the notes on the back side for polishing via the present invention.
f 裝 訂 線 -12- 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 經濟部智慧財產局員工消費合作社印製 478061 A7 B7__ 五、發明說明（1〇 ) 到約3 0至約500A之晶圓切口所需的時間大約爲1 5至3 0秒 ，而習知鹼性蝕刻劑所蚀刻晶圓所需的時間則爲3 0至6 0秒 。除此之外，從經由本發明蚀刻之晶圓除去以達所需粗糙 度的物質量爲約3至約6微米，相較之下，習知鹼性蝕刻劑 所蝕刻晶圓所需的則爲5至8微米。因此邊緣/切口拋光方法 的量率及生產量二者皆有所改善。 此外，由本發明所蝕刻之晶圓正面與背面皆有小於約 2800A，較佳小於約2500A，更佳小於約2000A且最佳小於 約1500A的粗操度，相較之下，習知鹼性蚀刻劑所蚀刻之 晶圓正面與背面則通常具有大於2800A的表面粗糙度，更 典型係大於3000A且可能有至少4500A或更大的的表面粗糙 度。因此，經由本發明所蝕刻晶圓，正面與背面所需的拋 光時間皆小於習知鹼性蚀刻劑所蚀刻之晶圓所需者。比如 説，利用一種習知拋光裝置如一 6 DZ拋光裝置（其市面上可 從斯特拉斯堡公司（Strasbaugh Co.，San Luis Obispo, California))拋光晶圓的正面及視情況的背面，其中一拋光 塾板（如一種市面上可從羅得爾公司（Newark，Delaware)所購 得之Suba拋光墊板）係以約4 0至約65 psi之拋光壓力施加在 溫度約2 0至約3 5 °C的晶圓表面上，當拋光台在當時以約8 0 至120 RPM之速度旋轉的同時，以約40至約100毫升/分的 速率添加一種含膠狀氧化矽之磨蚀混合物，且以約120至約 300毫升/分的流速添加一種鹼性溶液，其包含例如約1至約 3重量％金屬氫氧化物，其中該金屬氫氧化物包含pH大約 9.5至12之氫氧化鉀及/或氫氧化鈉。正面及/或背面係經拋 -13 - 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）~ (請先閱讀背面之注意事項再填寫本頁) 訂·· 丨線· 478061 A7 B7 五、發明說明（11 ) 光到約5至約2 Ο A的粗糙度，整體厚度變化小於約1微米且 局部厚度變化小於約0.2微米。 抛光經由本發明所蝕刻晶圓之正面或背面所需的時間大 約爲200秒’而拋光由習知鹼性蝕刻劑所蚀刻晶圓之正面或 背面所需的時間則大約爲3〇〇秒。因此表面拋光方法的生產 量係有所改善。 下列實例將説明本發明。 實例1 將P底石夕晶圓浸潰於一種9 〇 含4 5重量0/。KOH與〇 . 6重 量。/。H2〇2之蝕刻劑中。另外，將p -底矽晶圓浸潰於一種大 約9 0 C僅含4 5重量％ KOH之蝕刻劑中。相較於以純鹼性 蚀刻劑所姓刻之晶圓，由含4 5重量0/。KOH與〇 . 6重量％ H2〇2之姓刻劑所姓刻之晶圓呈現大幅減少的表面粗糙度。 圖1顯示當晶圓係利用本發明之蝕刻劑所製備時，其表面粗 糙度的改善情況，此乃相較於純鹼性的4 5重量。/。KOH蝕刻 劑，以等量的原料除去而言。 實例2 經濟部智慧財產局員工消費合作社印製 (請先閱讀背面之注意事項再填寫本頁) -線· 將P底矽晶圓浸潰於一種9〇°C含45重量％ KOH與0·ό重 量％ Η2〇2之蝕刻劑中。另外，將ρ +底矽晶圓浸潰於一種大 約90 C僅含45重量％ K〇H之蝕刻劑中。相較於以純鹼性 蚀刻劑所蝕刻之晶圓，由含4 5重量％ &〇11與〇 · 6重量％ Η2〇2之蝕刻劑所蝕刻之晶圓呈現大幅減少的表面粗糙度。 圖2顯示當晶圓係利甩本發明之蝕刻劑所製備時，其表面粗 糙度的改善h ;兄，此乃相較於純驗性的4 5重量％ Koh蚀刻f gutter -12- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 478061 A7 B7__ 5. Description of the invention (1〇) to about 30 The time required for a wafer incision to about 500 A is about 15 to 30 seconds, while the time required for a conventional alkaline etchant to etch a wafer is 30 to 60 seconds. In addition, the amount of material removed from the wafer etched by the present invention to achieve a desired roughness is about 3 to about 6 micrometers. In contrast, what is required for a conventional alkaline etchant to etch a wafer is 5 to 8 microns. As a result, both the throughput and throughput of the edge / notch polishing method are improved. In addition, both the front and back of the wafer etched by the present invention have a roughness of less than about 2800A, preferably less than about 2500A, more preferably less than about 2000A, and most preferably less than about 1500A. In contrast, conventional alkaline etching is known The front and back of the wafer etched by the solvent usually have a surface roughness greater than 2800A, more typically greater than 3000A and may have a surface roughness of at least 4500A or more. Therefore, the polishing time required for the front and back surfaces of a wafer etched by the present invention is less than that required for a wafer etched by a conventional alkaline etchant. For example, a conventional polishing device such as a 6 DZ polishing device (which is commercially available from Strasbaugh Co., San Luis Obispo, California) is used to polish the front and optionally the back of the wafer, where A polishing pad (such as a commercially available Suba polishing pad from Newark, Delaware) is applied at a temperature of about 40 to about 3 at a polishing pressure of about 40 to about 65 psi. On the surface of the wafer at 5 ° C, while the polishing table was rotating at a speed of about 80 to 120 RPM at that time, an abrasive mixture containing colloidal silica was added at a rate of about 40 to about 100 ml / min, and An alkaline solution is added at a flow rate of about 120 to about 300 ml / min, comprising, for example, about 1 to about 3% by weight of a metal hydroxide, wherein the metal hydroxide comprises potassium hydroxide having a pH of about 9.5 to 12 and / Or sodium hydroxide. Front and / or back are thrown through -13-This paper size applies Chinese National Standard (CNS) A4 (210 X 297 mm) ~ (Please read the precautions on the back before filling this page) Order ·· 丨 Line · 478061 A7 B7 V. Description of the invention (11) Roughness of light to about 5 to about 2 OA, the overall thickness change is less than about 1 micron and the local thickness change is less than about 0.2 micron. The time required to polish the front or back of the wafer etched through the present invention is about 200 seconds' and the time required to polish the front or back of a wafer etched by a conventional alkaline etchant is about 300 seconds. Therefore, the throughput of the surface polishing method has been improved. The following examples will illustrate the invention. Example 1 A P-base stone wafer was immersed in a 90% containing 4 5 weight 0 /. KOH and 0.6 weight. /. H2O2 in the etchant. In addition, the p-bottom silicon wafer was immersed in an etchant at about 90 ° C. containing only 45% by weight of KOH. Compared to wafers etched with a pure alkaline etchant, the weight of the wafer is 45/0. The wafers engraved with KOH and 0.6% by weight H2O2 have a significantly reduced surface roughness. Fig. 1 shows the improvement of the surface roughness when the wafer is prepared by using the etchant of the present invention, which is 4 to 5 weight compared to pure alkali. /. KOH etchant is to remove the same amount of raw materials. Example 2 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page) -Line · Immerse a P-bottom silicon wafer in a 90 ° C containing 45% KOH and 0 · ό wt% Η2 in the etchant. In addition, the p + bottom silicon wafer was immersed in an etchant of about 90 C containing only 45% by weight of KOH. Compared to wafers etched with a pure alkaline etchant, wafers etched with an etchant containing 45% by weight & 〇11 and 0.6% by weight Η202 have a significantly reduced surface roughness. FIG. 2 shows the improvement of the surface roughness when the wafer is prepared by removing the etchant of the present invention. Brother, this is compared to the purely etched 45% by weight Koh etching.
478061 Α7 五、發明說明（12 劑，以等量的原料除去而言。 實例3 將石夕晶圓浸潰於一種大約90°C含45重量。/。KOH與3重量 % H2〇2之蚀刻劑中。另外，將矽晶圓浸潰於一種大約9 〇乇 僅含45重量％ KOH之蚀刻劑中。之後在明亮燈光下目測檢 視所姓刻晶圓的邊緣，並測量粗糙度。結果係列示於表1， 顯π利用本發明蝕刻劑所蚀刻之晶圓表面外觀光亮且較不 粗糖’此乃相較於以純鹼蝕刻劑所蚀刻之晶圓。 測I邊緣粗輪度之後，拋光晶圓邊緣以除去晶圓邊緣上 、斤有的損傷。相較於以純驗性蚀刻劑所钱刻之晶圓，利用 本發明蝕刻劑所蝕刻之晶圓需要較少的邊緣拋光時間來除 去晶圓邊緣上的損傷，如表1所示。 ，以上述觀點，可見已達成本發明的幾個目的。因爲在上 述半導體基質平滑化方法中可做出各種變化而不達背本發 明範疇’因此計畫所有包含於上述説明中的事 ^明性而非限制意味。除此之外，當介紹本發明要3 A佳具體實例時’冠詞"一種，，、"此，·和，， —或多種要素。”包本"、"包括"、 〜欲/、有 性且们m 有$些詞則係總括 係^除了所列要素外可能還有其他的要素。 經濟部智慧財產局員工消費合作社印製 本紙張f度適用;國國家^7^4%各⑽χ 297公复） -15- 478061 A7B7 五、發明說明（13 ) 表1 鹼性蝕刻方法 粗糙度Ra (nm) 在明亮燈光下 的邊緣外觀 藉邊緣拋光除去 損傷所需的時間 標準腐蝕物 142.53 晦暗 至少3分10秒 修正腐姓物 68.54 光亮 1分24秒-1分56秒 (請先閱讀背面之注意事項寫本頁) 上5. !線- 經濟部智慧財產局員工消費合作社印製 -16- 本紙張尺度適用中國國家標準（CNS)A4規格（210 χ 297公釐）478061 Α7 V. Description of the invention (12 agents, with the same amount of raw materials removed. Example 3 The Shi Xi wafer was immersed in an etching at about 90 ° C and containing 45% by weight of KOH and 3% by weight of H2O2 In addition, the silicon wafer was immersed in an etchant containing approximately 90% and only 45% by weight of KOH. Afterwards, the edges of the inscribed wafer were visually inspected under bright light, and the roughness was measured. Results series As shown in Table 1, it is shown that the surface of the wafer etched by the etchant of the present invention is bright and less coarse. This is compared to the wafer etched with soda etchant. After measuring the rough roundness of the edge, the crystal is polished. Rounded edges to remove any damage on the wafer edges. Compared to wafers etched with purely etchant, wafers etched with the etchant of the present invention require less edge polishing time to remove the wafer The damage on the edges is shown in Table 1. From the above point of view, it can be seen that several purposes of the present invention have been achieved. Because various changes can be made in the above-mentioned semiconductor substrate smoothing method without departing from the scope of the present invention. Draw all included in the above description It is meant to be clear rather than restrictive. In addition, when introducing the present invention to be a 3 A specific example, the "article", "and," and ", and, or more elements." ", " Including ", ~~ /, sexual, and if you have some words, it is a summary system ^ In addition to the listed elements, there may be other elements. Printed by the Intellectual Property Bureau, Ministry of Economic Affairs, Consumer Consumption Cooperative Paper f degree is applicable; country and country ^ 7 ^ 4% each ⑽χ 297 public reply) -15- 478061 A7B7 V. Description of invention (13) Table 1 Roughness Ra (nm) of alkaline etching method under bright light The time required for edge polishing to remove damage. Standard corrosives 142.53 Obscured at least 3 minutes and 10 seconds Corrected rotten materials 68.54 Bright 1 minute and 24 seconds-1 minute and 56 seconds -Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs-16- This paper size applies to China National Standard (CNS) A4 (210 x 297 mm)